/***************************************************************************
 *   Copyright (C) 2008 by Eduardo Gurgel Pinho                            *
 *   edgurgel@gmail.com                                                    *
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 3 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 *   This program is distributed in the hope that it will be useful,       *
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
 *   GNU General Public License for more details.                          *
 *                                                                         *
 *   You should have received a copy of the GNU General Public License     *
 *   along with this program; if not, write to the                         *
 *   Free Software Foundation, Inc.,                                       *
 *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
***************************************************************************/

#ifndef __KD_TREE_H__
#define __KD_TREE_H__

#include <vector>

#include "photon.h"
#include "math/vector.h"

#include <boost/tuple/tuple.hpp>

using namespace boost::tuples;

namespace Sirat {

namespace Photon_Mapping {

struct Kd_Node {
	Kd_Node(const Math::Vector&,unsigned short);
	~Kd_Node(void);
	
	void add_left(Kd_Node*);
	void add_right(Kd_Node*);
	void add_photon(Photon*);

	Kd_Node* get_left(void) const;
	Kd_Node* get_right(void) const;
	Photon* get_photon(void) const;
			
	int get_height(void) const;

	Kd_Node* left;
	Kd_Node* right;
	Math::Vector point;  /* X,Y or Z */
	unsigned short dimension;
	Photon* photon;
};

struct Kd_Tree {
	Kd_Tree(void);
	~Kd_Tree(void);
	
	Photon* nearest_neighbour(const Math::Vector&) const;
	std::vector<tuple<Photon*,double> > k_nearest_neighbour(const Math::Vector&,const unsigned short,const double = -1.0) const;
	int get_height(void) const;
	void level_order(void) const;
	
	Kd_Node* root;
};

void insert_knn_list(std::vector<tuple<Photon*,double> >&,Photon*,const double&,double&,const unsigned short);

}

}

#endif
